Torque release wrench



y 1939- w. M. SIESEL 2,157,574

TORQUE RELEASE WRENCH Filed Nov.' 19, 1937 v NVENTO R Mum)!!! 512551:

Patented May 9, 19 39 I UNl'lED s- Es' PATENT; OFFICE 2,157,514 TORQUE-RELEASE wnENcn William M. Siesel, Verona, N. J.

Application November 19, 1937, Serial No. 175,361

12 Claims. (6164-49) This invention relates to torque overload release devices, being particularly concerned th improvements in torque limiting wrenches of a type adapted for field and shop use in connection with tightening nuts, bolts and the like on machinery. In highly developed machinery such as aircraft and automotive engines, the correct tightness of' 'nuts and bolts is a prime requisite for strengthage in his portable tool kitf'theprovision of a.

the annexed detailed description in connection with the drawing, in which:

Fig. 1 is an end elevation, partly in section, and Fig. 2 is a side elevation, partly in section. The device comprises a driving member In consisting of a circular web I I having an annular ring l2 integral therewith,,the ring having a plurality of radial holes i3, equally circumferentially 40 spaced, and of equal'diameter. A driving collar [4 extends from the web I I, having opposed radial holes I5 for the insertion of a turning bar. The collar I4 may, if desired, be arranged as a stand: ard wrench socket. Embraced by the ring I2 is a disc l6 having a plurality of radial holes I! extending from the disc outer edge inwardly to an axial bore l8, the disc being rigidly mounted on a concentric hub 19 integral with a counterbored 50 an open annulus, the left end' thereof as shown, having a tapered conformation as at 2|, so as to receive an axially movable collar 22 having,a

tapered or conical end as at 23. The collar 22 is '5 preferably screw-threaded on the shaft 20 as at 24,

shaft 20. The bore l8 defines with the shaft 20 so that it may be accurately adjusted axially.

jSuitable lines and characters, as shown, may be scribed on the collar and disc members to serve as indicia for presetting the releasing torque for a range of nut or bolt sizes. 1 5 Within each hole I! is a compression spring 26 engaging balls 21 and 28 and urging the balls apart into respective engagement with the ring l2 and the collar 22. The balls 21,- when corresponding holes l3 and H are allned, seat on the 10 edges of the holes 43, which are of smaller diameter than the balls, preventing relative turning of the members Ill and I6 until the torque is sufllcie'nt to overcome the force of the springs 26, when the balls l3 move inwardly and permit relative rotation. Axial adjustment of the 'collar 22 presets the initial compression of the several springs 26,

simultaneously, for torque release adjustment.

The order of torque to which the device is adapted may be controlled by the rate of the springs used, and also by the diameter of the holes I3. It is contemplated that the balls 21! and 28 and the ring l2, inparticular, be of wear-resistant .material, such as case-hardened or nitrided steel.

' The shaft 20 is provided at its right hand end I witha squared driving element 29 having a ball detent- 30 adapted for use with standard wrench sockets or attachments. The web H is held in assembled relation on the shaft 20 by a bolt 3i, threaded into the solid shaft end and being locked 30 thereto by a pin 32. I

The device as above described is a distinct improvement over analogous devices of the prior art in several respects. One dominant feature is that the.locking balls 21 act at nearly the extreme outer diameterof the whole device, permitting of maximum torsional effect, due to the long moment arm aiforded by the maximum radius of the device, while holding the bulk ofthe device to minimum size. As a specific example of the compactness of which a device according to the invention is capable, one capable of maximum torque release of 450 inch pounds weighs only two and a half pounds-and is 3.8 inches in diameter and 2.4

inches long. 1 It will be noted-that the major components of the device may be fabricated "by simple turning and drilling operations from bar and fiat stock with a minimum of wastage. 1

While I have described my invention in detail in its present preferredembodiment, it will be obvious to those slgilled in the art, after understanding my invention, that various changes and modifications may be made therein without de parting from the spirit or scope thereof. I aim in -l. ll torque overload release device comprising a ring member having a plurality of circumferem tially spaced radial holes, a disc member rotatably fitted within said ring having a similar plurality of radial holes, said disc having an axial bore, an arbor'upon which said ring and disc are mounted, a conically formed collar slidable axially into said bore, a compression spring in each disc hole, a ball at each end of each said spring, the inner balls bearing on said collar and the outer balls bearing upon the inner surface of said ring and upon the edges of the holes of the ring, said collar, according to its axial position, adjustably positioning the inner balls for initially compressing said springs, and driving attachments rigid with respective members.

2. A torque overload release device comprising a ring member having a plurality of circumferentially spaced radial holes, a disc member rotatably fitted .within said ring havinga similar plurality of radial holes, said disc having an axial bore, an arbor upon which said ring and disc are mounted, a conically formed collar slidable axially into said bore, a compression spring in each disc hole, a ball'at each end of said spring, the inner balls bearing on said collar and the outer balls bearing upon the inner surface of said ring and upon the edges of thetral hub, an annular bore, and radial holes opening to said bore; a conical-ended collar screwed on said hub into said bore, the conical end underlying said radial holes; balls in said holescontacting the collar; springs in said holes resting on the-balls; and outer balls in said holes engaged between said springs and the inner surface of said ring, said outer balls being registrable with the ring holes to hold said ring and disc from relative rotation.

4. A torque overload release device comprising a circular web having a ring at its outer periphery, said ring having a plurality o; radial holes around its peripheryfia disc having a central hub, an annular bore, and radial holes open- 'ing to said bore; a conical-ended collar screwed on said hub into said bore, the conical end underlying said radial holes; balls in said holes contacting the collar; springs in said holesrestin'g on the balls; outer balls in said holes engaged between said springs and the inner surface of said ring, said outer balls being registrable with the ring holes to hold said ring and disc from relative rotation, and driving attachments respectively rigid with said web and hub.

unitary means for controlling the force on said spring-pressed detents.

6. A torque overload release device comprising concentric members, one embracing the other, having an equal plurality of radial holes all in one plane normal to'the axis of said members,

'the holes in the outer member being smaller therein, an embracing ring member having apertures, spring-pressed detents in said gindeways urged outwardly for engagement with said apertures when the latter are alined with the guideways, and unitary means for coincidentally con trolling the force on said spring pressed detents.

8. A torque overload release device comprising a member having a plurality of open-end guideways equally spaced about an axis of the member, a spring in each guideway, a detent pressed by each spring in one end of each guideway, a second member rotationally movable relative to the first member having recesses within which said detents are adapted to engage, and unitary means movable on said first member for coincidentally adjusting the several springs for presetting the amount of torque necessary between said members to unseat the detents from said recesses.

9.. A torque overload release device comprising a circular member having a plurality of guideways formed therein, a, second member having a plurality of recesses, Idetents in the guideways engageable with the recesses, springs in said guideways pressing respective detents, and unitary means for coincidentally adjusting the force exerted by said springs on said detents.

10. A torque overload release device comprising a circular member having a. plurality of guideways formed therein, a second member having a plurality of recesses, detents in the guideways engageable with the recesses, springs in said guideways pressing respective detents, and unitary means adjustable axially of said circular member for coincidentally adjusting the force exerted by said springs on said detents.

11-. A-torque overload release device comprising a substantially cylindricalmember having a plurality of angularly spaced substantially radial guideways therein, said member having a central bore, an embracing ring having apertures registrable with said guideways, spring pressed detents in said guideways, and a bushing in said bore the surface of which provides a bottom rest and reaction member for the springs of said detents, said detents being urged outwardly into engagement with said ring.

12. A torque overload release device comprising a member having a plurality of radial guideways therein, detent elements, movable in said guideways, an apertured ring embracing the member the apertures thereof being registrable with said detents, springs urging said detents into engagement with said apertured ring, and a movable concentric element in said member engaged by said springs and forming a reaction member therefor.

WILLIAM M. SIESEL. 

